In surgery a necessity of long draining of cavities often arises. Drainage of various designs is used for this purpose, the appliances are inserted into the drained cavity, ensuring active or passive aspiration. The main and so far unsolved problem of prolong drainage of cavities remains maintaining of permeability of drainage and ensuring the natural process of gradual constriction of wound channel as the cavity heals. Unfortunately despite constant perfection of the design of drainage systems, the drainage opening after some time is obturated with fibrin's clot. In this case drainage is removed and a new drainage system is installed into the drained cavity. Unfortunately it is practically impossible to insert a new drainage into the drained cavity using the old wound passage. This is explained by two main reasons. Firstly, the wound passage is of winding shape on the spot of the removed drainage system and it is practically impossible to lead a new drainage through all its turns. Secondly, fibrin's clots that are found inside the passage of the removed drainage is fixed inside the cavity and is partially preserved inside the passage of the wound channel after the drainage system is removed. The remaining clots prevent insertion of a new drainage strictly along the old wound channel, it may be infected and promote inflammatory process inside the wound channel, decelerating the healing of the cavity and the wound channel. In such cases in order to obtain prolong drainage of cavities an old drainage is removed after it has been obturated with fibrin clots and a new drainage system is installed, using a new wound channel. Several problems arise here. Firstly, it is impossible to lead a new drainage along a new passage strictly to the spot where the end of the old drainage was, thus making the process of cavity's draining inadequate. Secondly, formation of a new wound channel will further traumatize the tissues and may provoke generalization of the infection inside the drained cavity. Thirdly, the presence of fibrin clot inside the old wound channel will promote the inflammatory process inside it.
The appliance for drainage of cavities through skin is known [V. G. Ivshin An appliance for drainage of cavity formation via skin//Surgery—1998.—No 8.—p. 49-50.], this appliance presents a needle with an external cannula, installed non-stationary upon it and drainage to be inserted into the drained cavity along a new wound channel, supervised by ultrasonic testing.
The drawback of this system is impossibility of its insertion along the old wound channel and the necessity to use expensive and technically complicated equipment.
Another design includes drainage tube [A. M. Moroz Drainage tube with centimeters points//Clinical surgery.—1969.—No 5—p. 35.], which presents a spherically closed end of children stomach pump. Before application all necessary holes are made in the tube and it is inserted into the desired depth. According to its author this tube can easily be substitutes, by means of a metal mandrel.
The main drawback of the drainage tube of such design is the absence of a butt hole, thus making the process of drainage ineffective. It is not possible to reinstall the drainage, using a mandrel, as specified by the author.
A model of a drain tube, functioning for a long time is also known [V.I. Shaposhnikov—A design of a drainage tube of a prolong action//Vestnik Khirurghii (Messenger of Surgery).—2002.—No 5—p. 81-83.], it was chosen as prototype which specifies the possibility of regulating the permeability of drainage by inserting a bead fixed on a fishing line, both ends of the line are drawn outside. By means of constant drawing of the bead backwards and forwards along the tube's body constant destruction of fibrin clots, precipitated into the drainage passage is performed, due to traction on the line's ends. The authors also specify periodic shift of the drainage system alongside its length, within 1-2 cm, 4-6 times a day.
The drawback of this design, chosen as a prototype is the necessity of location of both ends outside, thus making it impossible to apply it in the bulk of clinical situations, when drainage has to be inserted from one side only. Besides, the drained cavity may get infected when the bead is moved, through a piece of fishing line that was led outside. An organizational difficulty of application of such type of drainage that supposes constant bandaging (up to 6 times a day) may be considered another drawback.
The present invention solves the problem of ensuring the possibility of removing the clot inside the drainage opening, but fixed by one end inside the wound cavity during the drainage removal, as well as ensuring the possibility of reinstallation of the drainage with smaller inside diameter, strictly along the old wound channel, irrespective of length and direction of the latter.